Independent load flasher



Aug. 16, 1966 w. B. ALMASSY 3,257,330

INDEPENDENT LOAD FLASHER Filed A 27, 1963 INVENTOR 70 MALI/1M6 41/77413/ATTOR 5Y5 United States Patent 3,267,330 INDEPENDENT LOAD FLASHERWilliam B. Alrnassy, Pine Brook, .N.J., assiguor to Tung- Soi ElectricInc, a corporation of Delaware Filed Aug. 27, 1963, Ser. No. 304,822 1Claim. (til. 315209) The present invention relates to flashers of thetype adapted for use for directional signals in trucks or the like andcomprises a novel three terminal flasher in which the flashing rate andratio is independent of the lamp load and in which positive pilotindication is provided.

A feature of the invention is the use in the flasher of a reed relay incombination with a snap switch operating in response to expansion andcontraction of a pull means with change in temperature. The flasher ofthe invention may be incorporated in a variety of circuits andpreferably such circuits provide that the lamp load and the pull means,or heater for the pull means, will be connected in parallel to insureindependence of the flashing rate from theload.

In its simplest embodiment the invention comprises a snap switch of thetype disclosed and claimed in Schmidinger Patent No. 2,761,931 withwhich is associated a reed relay thenormally open contacts of which areconnected in series with a heater for the pull wire of the snap switchand the coil of which is connected in series with the normally closedcontacts of the snap switch. The snap switch and reed relay are mountedin close proximity on an insulating base provided with three terminalsfor connection to a source of potential, to the load and to a pilotsignal. When a large number of lamps comprise the lamp load the newflasher preferably includes a relatively powerful relay for controllingthe contacts in the circuit of the load.

For a better understanding of the invention and of specific embodimentsthereof reference may be had to the accompanying drawings of which:

FIG. 1 is a side view partially broken away of a flasher embodying theinvention.

FIG. 2 is a diagram of suitable circuit connections for the device ofFIG. 1.

FIG. 3 is a diagram representing an alternative circuit arrangement forthe device of FIG. 1.

FIG. 4 is a side view of a heavy duty alternate load flasher embodyingthe invention; and

FIG. 5 is a diagram showing a circuit arrangement for the device of FIG.4.

In FIG. 1 a snap switch of the general type of that of the abovementioned Schmidinger patent is indicated generally by the referencenumeral 2. It comprises a frame 4, a snap plate 6 the upper end of whichis welded to the frame 4, and the lower end of which carries contactsfor engagement with fixed contacts 8 and 10. A finger 12, extending fromthe frame 4, has secured to it one end of a wire 14 the other end ofwhich is fastened under tension to one arm of an L-shaped anchor member16. The other arm of the anchor member 16 is welded to a vane 18 definedby two closed ended longitudinal slots cut in the plate 6. The tensionin the wire 14 is such as to maintain the lower end of the plate 6 inengagement with the fixed contact when the wire 14 is cold. For a betterunderstanding of the construction of the snap action device 2 referencemay be had to the above mentioned patent.

In the particular construction of FIG. 1 expansion of the pull wire 14is effected by means of a heater winding 20 comprising very thin wirehaving an insulating ceramic coating thereon. A prong terminal 22 issecured to the under side of a base 24 of insulating material by meansof fingers 26 which pierce the base. Above the 3,267,330 Patented August16, 1966 base the fingers are bent over a horizontally extending portionof the frame 4 to clamp the frame to the base. Also mounted on the base24 by means of fingers of a prong terminal 28 is a reed relay, indicatedgenerally at 30, and comprising a glass tube 32 and coil 34 surroundingthe tube. Within the tube 32 are reed contacts 36 and 38 which arenormally out of engagement but which are brought into contact when thecoil 34 is energized. Contact 38 is connected through the lower end ofthe tube 32 to a support element 40 for the relay. Contact 36 isconnected through the upper end of the tube to one end of the heater 20for the pull wire. One end of the relay coil is connected to a thirdprong terminal 42 and the ot-herend of the relay coil is connected tothe normally closed contact 10 of the snap switch.

The operation of the structure of FIG. 1. and the circuit thereof willbe better understood by reference to FIG. 2 in which the structure ofthe snap plate is only diagrammatically shown and in which thesupporting means for the reed relay and for the snap plate are notshown. As shown, in FIG. 2, terminal 22 through a manually operatedswitch S is connected to a source of power, indicated as a battery 44,which may be a car or truck carried battery. The negative terminal ofthe battery is grounded as is terminal 28. A lamp load to be flashed,which may comprise two signal lamps 46 and a pilot lamp 48 all inparallel, is connected between terminal 42 and ground. When switch S isclosed current flow from the battery through the snap plate, normallyclosed contact 10, coil 34 and the lamp load to ground. This currentwill be suflicient to light the lamps and to energize the reed relay.Upon energization of the reed relay, contacts 36 and 38 thereof close,thus closing a circuit from the battery through the heater 20 andthereed:

contacts to terminal 28 and ground. The heat generated in the heaterwill cause expansion of the pull wire 14 which, after a predeterminedtime, will expand to a point where the snap plate moves out ofengagement with contact 10, thus opening the circuit of the relay coiland of the lamps. The lamps thus become extinguished and the reedcontacts thus open, opening the circuit of the heater. When the pullwire cools sufliciently, the snap plate moves back into position toclose the circuit of the relay coil and the cycle repeats. With theforegoing circuit, because the lamp load is not in series with theheater at any time, variation in current through the lamps will notchange the rate of flashing, that is the rate of expansion andcontraction of the pull wire. Any number of lamps may be flashed in thelamp load provided the reed relay is initially adjusted for the expectedload. Such adjustment may be affected by change in position of the relaycoil on the tube 32 or by change in the number of turns in the relaycoil. Once the reed relay is adjusted for the desired lamp current, ifone lamp burns out the current through the reed relay will beinsufficient to cause the relay contacts to close. Accordingly, the pullwire will remain cold and the remain-ing lamps and the pilot lamp willburn steady giving a positive pilot indication;

In the circuit of- FIG. 2 only the normally closed contact of the snapplate are employed and pilot and signal lamps are connected in parallelbetween the terminal 42 and ground. If it is desired to employ thestructure of FIG. 1 in a device that alternately energizes two loads thecircuit of FIG. 3 may be employed without change in structure of thedevice. In this circuit terminal 22 is connected through switch S tobattery 44 as in FIG. 2. Terminal 22 is also connected to the snap plateand to one end of the heater 20. The other end of the heater isconnected through the relay contacts to terminal 28. The relay coil isconnected between the norm-ally closed contact 10 of the snap plate andterminal 42. The-- normally open contact 8 of the snap plate isconnected to terminal 28. Terminals 28 and 42 are respectively connectedthrough lamp loads 50 and 52 to ground for alternate energization of thetwo lamp loads with expansion and contraction of the pull wire. When theswitch is closed current flows through the normally closed contact 10and relay coil to energize the lamp load 52 connected to terminal 42.Energization of the relay coil closes the circuit for the heater and forthe load 50 connected to terminal 28. As the heater is in series withthe load 50 the current will be insuflicient to cause the lamps of thatload to light. When however, the pull wire is expanded sufliciently tocause the snap plate to move out of engagement with contact 10 andengage the contact 8 the heater is shunted and the lamp of load 50receive full voltage from the battery. At the same time the circuit forload 52 is opened at contact 10. The reed contacts then open, openingthe circuit of the heater and permitting the pull wire to cool. Thus,with this circuit arrangement, the lamp loads are alternately flashed.Load 52 being connected with the normally closed contact 10 will noteffect the rate of flashing. The lamp load 50 which is energized throughthe normally open contact 8 also will not effect the flashing rate.Thus, the circuit of FIG. 3 is that of an alternate flasher independentof load So far as pilot action is concerned, if a lamp of load 52 burnsout the remaining lamps of load 52 will remain steady on, and the lampsof load 50 will remain steady ofl as the relay contacts will not close.

In FIG. 4 there is shown a heavy duty flasher of the general type ofthat of FIG. 1 but incorporating an additional relay. The flasher ofFIG. 4 includes a relatively extended base member 54 of insulatingmaterial provided with prong terminals 22, 42 and 28 as in theembodiment of the invention illustrated in FIG. 1. Fingers of the prongterminals support the snap switch 2 and reed relay 30. On the remainingportion of the base 54 is mounted a relay coil 56 which is supported ona horizontal leg of a right angle bracket 58. Between the relay windingand the snap switch 2 is an insulating wall 60 through which conductorsextend for connections to the relay winding and to the movable contactsof the relay. Hingedly mounted on the upper end of the vertical leg ofbracket 58 is an armature 62 which is spring biased by a relativelyheavy spring 64 away from the core 66 of the relay 56. A thin plate 68of insulating material is mounted on the armature 62 and supports a pairof leaf springs 70 (only one being visible in the view of FIG. 4). Theseleaf springs are connected through leads 72 to connecting pins extendingthrough the wall 60. The spring 64 biases contacts carried by the leafsprings 70 into engagement with fixed cont-acts mounted on connectorsextending through the wall 60. No attempt has been made in the drawingof FIG. 4 to shows the various electrical connections of the structureas these will be apparent from the diagram of FIG. 5 to which referencemay now be had.

Terminal 22 as in the structure previously described, is connectablethrough the switch S to the positive terminal of battery 44. Theterminal is also connected to the snap plate and through the normallyclosed contact to the heater for the pull wire and to one contact of thereed relay, the other contact of the reed relay, being connected toterminal 28. The normally open contact 8 of the snap plate is connectedto one end of the relay winding 56, the other end of the Winding 56being connected to terminal 28. Terminal 22 is also connected to theleads 72 leading to the contact carrying leaf springs 70. The normallyclosed contacts associated with the leaf springs are connected to oneend of the reed relay coil 34, the other end of which is connected toterminal 42. A pilot lamp 48 may be connected between terminal 28 andground, and a lamp load, shown as lamps 46, may be connected betweenterminal 42 and ground. With the described circuit when the switch isclosed current flows through the normally closed contacts of the relay56 and through the coil 34 of the reed relay to light the lamps 46. Thiscurrent energizes the reed relay to close its contacts whereupon currentflows through the heater 20 and the pilot light 48. The pilot light willnot light because of the resistance of the heater 20 in seriestherewith. However, the heater will cause expansion of the pull wire andconsequent snapping of the snap plate from engagement with contact 10into engagement with contact 8. This energizes the relay 56 to open thenormally closed contacts thereof. The current through the relay 56 willbe suflicient to light the pilot lamp. The movement of the snap plateopens the circuit of the heater 20 which thereupon cools to contract thepull wire. The opening of the contacts of relay 56 cuts off the currentto the reed coil to open the reed contacts. Thus, when the pull wire hascooled suflicient to cause the snap plate to move back into engagementwith contact 10 the circuit through the heater is open at the reedcontacts and remains open until relay 56 release to permit the contactscarried by leaf springs to close the circuit through the coil of thereed relay. Lamps 46 are extinguished when relay 56 is energized becausethe circuit thereof is open at the relay contacts. Pilot lamp 48 isdimmed when the relay 56 is deenergized because the resistance of heater20 is then in series with the pilot lamp. Thus the device operates toalternately flash the lamp loads connected to terminals 28 and 42. Ifone of the lamps connected to terminal 42 burns out the current throughthe reed coil will be insufficient to cause closure of the reed contactsand hence heater 20 and relay 56 cannot be energized and the lamp 48will be steady off. The remaining lamp of the load connected to terminal42 will be steady on.

With the powerful relay of the structure of FIG. 4 any number of lampsmay be connected in the circuit connected to terminal 42 and hence thisflasher has a wide utility for use on trailer trucks or the like wheremany signal lamps or warning lamps are to be flashed.

The invention has now been described in connection with two specificconstructions. Although in each of the illustrated embodiments of theinvention the pull means of the snap switch have been shown ascomprising a tensioned wire having a heater wound about it forcontrolling contraction and expansion of the pull wire, obviously thepull means could comprise the wire itself in series with a ballastresistor as in the flasher of the above mentioned Schmidinger patent.Thus in the circuits of FIGS. 2, 3 and 5 the heater 20 can be consideredas a pull wire and ballast resistor. Although the particular snap plateshown in the said Schmidinger patent and diagrammatically illustratedherein is preferred in the structure of the device of the invention,obviously other snap acting hot wire controlled flashers could beemployed in the structure of the invention. For example, the hot wirecontrolled snap plate of Siiberg Patent 3,052,780 could be substitutedfor the illustrated snap plate.

Various other changes may be made in the described constructions andvarious alternative circuit arrangements can be employed withoutdeparting from the spirit of the invention or the scope of theaccompanying claim.

I claim:

A three-terminal independent load flasher comprising coil and normallyopen contacts which close when the current through the coil exceeds apre-determined value, one of said reed relay contacts being connected tothe other end of said heater and the other of said reed relay contactsbeing connected to a second one of the terminals, said relay coil beingconnected between said fixed cont-act and the third one of saidterminals, whereby when a source of potential and a lamp load to beflashed is connected across the first and third terminals and the sourceof energy is connected across said first and second terminals the lampload will be flashed when the current therethrough exceeds saidpredetermined value and will remain steady-0n when the current throughthe load falls below said pre-determined value.

References Cited by the Examiner FOREIGN PATENTS 1,155,115 4/1958France.

10 JOHN W. HUCKERT, Primary Examiner.

A. M. LESNIAK, Assistant Examiner.

